#include <string>
#include <vector>

namespace S1 {
    class Solution {
    public:
        void reverseString(std::vector<char>& s) {
            int i = 0;
            int j = s.size() - 1;

            while (i < j)
            {
                std::swap(s[i], s[j]);
                // auto c = s[i];
                // s[i] = s[j];
                // s[j] = c;

                i++;
                j--;
            }
        }
    };
}


int main() {

    S1::Solution s;
    std::vector<char> s1 = {'H', 'a', 'n', 'n', 'a', 'h'};

    s.reverseString(s1);


    return 0;
}